Childhood obesity is a major public health concern. Substantial amount of evidence suggests that maternal obesity is a significant independent factor for childhood obesity. Evidence suggests that infants born to obese women are more likely to have higher birth weights (large-for-gestational-age, LGA, e90th percentile for weight and gestational age), and are at greater risk for developing obesity, type 2 diabetes (T2DM) and metabolic syndrome in later life. LGA infants are more likely to have a prolonged period of decreased insulin sensitivity, beginning in the neonatal period and extending throughout childhood. Until recently, research has emphasized the association between large birth size and the consequences of metabolic dysregulation on peripheral organ systems. However, there is increasing evidence that persistent hyper insulinemic or insulin resistance state may have significant consequences for the central nervous system (CNS). The mechanism for this risk is not known;however, investigators have focused mechanistic studies on the potential role of the hippocampus, a discrete brain region with a dense population of insulin receptors, in age-related cognitive decline. Concern about the effects of metabolic dysregulation on health is not limited to adults. There is growing concern that these metabolic changes may have significant effects on the brain in early life. Given the increasing number of obese women of childbearing age, coupled with the large body of research linking maternal pregnancy weight with child metabolic abnormalities, there is a critical need to investigate the association between maternal and child obesity with brain development and function. The overall goal of this project is to examine the relationship between maternal pregnancy factors, large birth size, and child obesity on child cognitive abilities using a national longitudinal sample. This goal aligns with the National Institute of Nursing Research strategic plan for promoting health of children by identifying at-risk children for untoward consequence of obesity. It is hypothesized that children exposed to hyper nutritional environments during the intrauterine period will exhibit lower cognitive abilities than those who had no such exposure;and children who themselves are obese at primary school age (5 to 7 years) will have lower cognitive ability than LGA infants not obese at primary school age. The current study takes a descriptive observational approach to address the knowledge gaps. This study uses data from the National Longitudinal Survey of Youth,1979 mother-child files (NLSY79) to examine the relationship between maternal weight, child weight, and birth size on child's global cognitive ability, measured at primary school age. Regression analysis will be used to examine the association between cognitive test scores and a quadratic function of birth weight, and test for an independent effect of child weight status and whether it mediates the effect of birth weight on cognition, controlling for child and family background characteristics. PUBLIC HEALTH RELEVANCE: Maternal obesity and excessive weight gain during pregnancy may result in detrimental effects on the child's brain development and general health. This research explores the link between maternal obesity, large size infants, and early childhood obesity, on child's cognitive ability. The results of this research may provide insight in developing public health strategies for preventing untoward consequence of childhood obesity epidemic.